As illustrated in FIGS. 1 and 2, in general, a heavy-duty metal demolition shears 10 of the sort in which a lubricating system according to the invention may be incorporated has a stationary lower jaw 12 and an upper jaw 14 that pivots about a pivot structure 16 to open and close. A hydraulic cylinder 18 drives the upper jaw 14 to open and close the shears 10. The shears 10 includes upper primary and secondary blade insert members 20 and 22, respectively, attached to seating surfaces on the upper jaw 14, and lower primary and secondary blade insert members 24 and 26, respectively, attached to seating surfaces on the right-hand lower jaw side plate 12b. The blade insert members 20-26 cooperate to cut material being processed with the shears 10 in shearing fashion. The lower jaw includes tow sides and an end plate. The blade side is often referred to as the “cutting side,” the opposite side, with the guide blade, is often referred to as the “guide side,” and the end plate is often referred to as the “cross plate.”
As the shears cut a workpiece, the upper jaw 14 may be deflected somewhat laterally due to the fact that the lines along which cutting forces are applied to a workpiece by the lower and upper jaws 12, 14 are slightly offset with respect to each other. Therefore, a heavy-duty demolition shears may include a wear guide or guide blade 28 attached to a seating surface formed along a slot-facing surface of the left-hand (guide side) lower jaw side plate 12a and a wear plate 30 that is attached to a lateral surface of a front or nose portion of the upper jaw.
Additionally, it is known in the art to provide one or more lateral blade stabilizers (not included in the prior art shears illustrated in FIGS. 1 and 2) that are positioned on either side of the upper jaw, generally near the pivot structure.
As the shears 10 operates, these various wear components, which present various wear surfaces, slide past each other—blade insert members past blade insert members, the wear plate past the guide blade, and the upper jaw past the lateral blade stabilizers. As they do so, they can wear each other down. Accordingly, it is known to lubricate the various wear surfaces that make sliding contact with each other. Traditionally, such lubrication has been done manually. That, however, necessitates stopping operation of the shears, which reduces productivity.